Water kefir grains - help!

Hi all - I’m new to making water kefir and am about to start my first batch.

I bought a pouch of ready-to-use grains, more than I’ll need for my first batch.

All instructions say to strain out the grains after the first fermentation and to store them in the fridge. This is where I need your help! Can I return the grains to the original pouch with the unused grains or should I store them separately?

Sorry if this seems an obvious question! Thanks for your help!